1. Field of the Invention
The present invention relates to a vapor-liquid separator for separating the liquid phase from a vapor-liquid two-phase fluid in the form of liquid droplets.
2. Description of the Related Art
Conventionally, a so-called cyclone vapor-liquid separator has been known as a vapor-liquid separator for separating the liquid phase from a vapor-liquid two-phase fluid in the form of liquid droplets. The cyclone vapor-liquid separator includes a cylindrical container; an introduction tube for introducing a vapor-liquid two-phase fluid into the container along a direction tangent to the cylindrical inner wall surface of the container; a delivery tube disposed on the center axis of the container and adapted to deliver to the exterior of the container the vapor phase remaining after separation of the liquid phase; and a discharge tube for discharging the separated liquid therethrough to the exterior of the container from a bottom portion of the container.
In the cyclone vapor-liquid separator, the vapor-liquid two-phase fluid introduced into the container from the introduction tube flows in a swirling state toward the center axis of the container from the cylindrical inner wall surface of the container. Centrifugal force generated in the vapor-liquid two-phase fluid causes the liquid phase, which is of higher specific gravity than the vapor phase, to fly toward the cylindrical inner wall surface of the container, thereby separating the liquid phase from the vapor phase. The separated liquid phase impinges on the cylindrical inner wall surface of the container to thereby be formed into liquid droplets. The thus-formed liquid is discharged to the exterior of the container from the discharge tube. The vapor phase remaining after separation of the liquid phase is delivered to the exterior of the container from the delivery tube disposed on the center axis of the container. In this manner, the vapor and liquid phases of the vapor-liquid two-phase fluid are separated from each other.
In the cyclone vapor-liquid separator, the vapor-liquid two-phase fluid introduced into the container from the introduction tube has predominantly a circumferential velocity component in the stage of swirl flow, whereas, in the subsequent stage where the vapor phase converges to the vicinity of the center axis of the container and enters the delivery tube through its opening portion, an axial velocity component becomes predominant. This abrupt change from the circumferential velocity component to the axial velocity component induces a relatively large pressure loss in a flow of the vapor-liquid two-phase fluid.